The invention relates to a method and a system to provide remote passive identification of components deployed in an optical fiber transmission system.
Optical fiber transmissions typically have a central office acting as a traffic hub for all telecommunication channels supported on the passive optical network. Further, the passive optical network comprises the network nodes which form the end points for the communication channels. Each remote node of the passive optical network can comprise a transponder or transceiver which terminates a data channel which originates or terminates in the central office at the other end of the optical link. The passive optical network add/drop optical filters are provided corresponding to each channel wavelength. These add/drop optical filters of the passive optical network can be placed at the same or at a different location as the transceivers of the remote nodes. The add/drop filter is spliced along the length of a network fiber of the passive optical network and forms an integral part of the passive optical network. The add/drop optical filters can remain in place during an operation lifetime of the passive optical network, while the transponders or transceivers of the remote nodes are added, removed or replaced according to the needs of the network operator at the remote locations. The network operator of the passive optical network needs to have access to inventory and topology information regarding components and modules available in the respective optical network at any point in time. While the equipment located at the remote nodes of the passive optical network can provide such inventory information, there is currently no method available to remotely detect the type of add/drop filters available in the passive optical network and their location along the network fiber of the passive optical network. Accordingly, network operators cannot determine a location of filters, in particular add/drop filters across such a conventional network. In conventional systems network operators rely on the installer to have connected the correct filter at each side and on inventory documentation manually entered or written by the respective installer. As a consequence, errors during installation can occur in this process and information, in particular inventory information concerning the add/drop filters can be lost. The only possible remedy involves dedicated visits by the network operator to the remote nodes or remote sites which is time-consuming and cumbersome for the respective network operator.
Filter networks with dedicated communication channels between the nodes such as an optical supervisory channel OSC can derive inventory information about filter placement provided that the filters are equipped with an ID chip. Further, this conventional network requires that an electrical power is available at the filter add/drop location. However, in a passive optical network PON most filters, in particular add/drop filters, are not provided with electrical power so that a network operator cannot retrieve inventory information regarding the filters, for instance via a dedicated communication channel such as an optical supervisory channel.
Accordingly, it is an object of the present invention to provide a system and a method that allows remote passive identification of channel add/drop filters deployed in an optical fiber transmission system.